System til afkodning af digitale videosignaler

摘要

The invention relates to a method and arrangement for deriving an ancillary signal from a compressed digital video signal (e.g. MPEG). The DC coefficients of autonomously encoded pictures (I-pictures) are selected from the compressed signal. The ancillary signal thus obtained can be used for display in a (multi-) picture-in-picture television receiver. A decoder for decoding such an ancillary signal is considerably simpler and less expensive than a full-spec MPEG decoder.